Pipeline Connecting Device, Pipeline Element Coupling Piece and Coupling Method Therefor

Abstract

Disclosed are a pipeline connecting device, a pipeline element coupling piece and a coupling method therefor. The pipeline element coupling unit comprises a plurality of coupling units, a gasket arranged at the coupling unit, and a fastening element. Each coupling unit comprises two engaging keys located at two coupling ends thereof, each engaging key has an engaging surface, and each engaging surface has a variable curvature radius. The fastening element is coupled to the coupling unit, wherein the pipeline element coupling piece is adapted to be pre-mount onto the two pipeline elements and be aligned with engaging keys and corresponding grooves of the pipeline elements. When the fastening element is operated to fasten together the coupling units, each engaging surface is deformed to change the curvature radius to substantially match the curvature radius of the groove circumference of the bottom of the groove of the pipeline element.

1 . A pipeline element coupling piece for coupling at least two pipeline elements each having a groove and a groove circumference at a groove bottom of the groove, wherein the pipeline connecting device comprises:
 two or more coupling units, wherein each of the two or more coupling units includes two engaging keys respectively, wherein each of the engaging keys has an engaging surface having a variable radius of curvature;   a least one gasket disposed in a cavity defined between the two or more coupling units; and   at least one fastening element configured for fastening the two or more coupling units together for pre-sleeving at the at least two pipeline elements while aligning the engaging keys with the grooves of the at least two pipeline elements, such that when the at least one fastening element is operated to fasten the two or more coupling units together, the engaging keys are engaged in the grooves of the at least two pipeline elements and each of the engaging surfaces is deformed to vary the variable radius of curvature so as to substantially match with a radius of curvature of each of the groove circumference of the groove bottom of each of the at least two pipeline elements.   
     
     
         2 . The pipeline element coupling piece, as recited in  claim 1 , wherein each of the engaging surfaces of the two or more coupling units defines a curve with variable radius of curvature selected from a group consisting of one or a combination of a logarithmic spiral curve, an Archimedes spiral curve, a pascal spiral curve, an ellipse curve, and a high power curve. 
     
     
         3 . The pipeline element coupling piece, as recited in  claim 1 , further comprising at least one pivot connecting element, wherein the two or more coupling units include a first coupling unit and a second coupling unit and the at least one pivot connecting element is configured to pivotally connect the first and second coupling units. 
     
     
         4 . The pipeline element coupling piece, as recited in  claim 3 , wherein each of the two coupling units comprises a housing, a pivot connecting end portion integrally extended from the housing and a fastening end portion integrally extended from the housing, wherein the pivot connecting end portions of the first and second coupling units are pivotally connected with each other by the at least one pivot connecting element, and the fastening end portions of the first and second coupling units are configured to be fastened by the at least one fastening element. 
     
     
         5 . The pipeline element coupling piece, as recited in  claim 3 , wherein each of the engaging surfaces of the first and second coupling units defines a curve with variable radius of curvature which is a logarithmic spiral curve. 
     
     
         6 . The pipeline element coupling piece, as recited in  claim 4 , wherein each of the engaging surfaces of the two coupling units has a proximate end point adjacent to the pivot connecting end portion thereof and a distal end point adjacent to the fastening end portion thereof, wherein the radius of curvature of each of the engaging surfaces gradually increases from the proximate end point to the distal end point. 
     
     
         7 . The pipeline element coupling piece, as recited in  claim 6 , wherein the radius of curvature at the proximate end point of each of the engaging surfaces is configured for equaling to a radius of curvature of the groove circumference of the groove of the pipeline element. 
     
     
         8 . The pipeline element coupling piece, as recited in  claim 7 , wherein each of the pipeline elements comprises an enlarged coupling end portion, wherein the radius of curvature of the distal end point of each of the engaging surfaces is not smaller than a radius of curvature of the enlarged coupling end portion. 
     
     
         9 . The pipeline element coupling piece, as recited in  claim 6 ,
 wherein each of the engaging surfaces defines a logarithmic spiral curve having an equation of ρ=e θ , wherein θ has a range of 0−180°, wherein ρ 1  denotes the radius of curvature at the proximate end point, ρ 2  denotes the radius of curvature at the distal end point, D1 denotes a diameter of the groove circumference of the groove, and D2 denotes a diameter of the enlarged coupling end portion, wherein ρ 1 =D1/2, ρ 2 =D2/2+R, wherein R has a value range of 0.3-1 mm.   
     
     
         10 . The pipeline element coupling piece, as recited in  claim 6 , wherein a deformation of each of the engaging surfaces results in deformed and varied radiuses of curvature thereof, wherein a variation range thereof is 4.5% to 12%. 
     
     
         11 . The pipeline element coupling piece, as recited in  claim 6 , wherein D denotes a distance between the proximate end point and the distal end point, wherein a deformation of each of the engaging surfaces results in variation of D, wherein a variation range thereof is 4% to 15%. 
     
     
         12 . The pipeline element coupling piece, as recited in  claim 6 , wherein the fastening element includes a bolt and a nut for coupling with the bolt, wherein each of the pivot connecting end portions has a connecting hole and the pivot connecting element is a pivotal pin configured to pass through the connecting holes to connect the pivot connecting end portions, wherein each of the fastening end portions has a fastening hole and the fastening element is configured to pass through the fastening holes of the fastening end portions. 
     
     
         13 . The pipeline element coupling piece, as recited in  claim 1 , further comprising a first pivot connecting element and a second pivot connecting element, wherein the two or more coupling units include a first coupling unit, a second coupling unit and a third coupling unit, wherein the first pivot connecting element is configured to pivotally connect the first coupling unit and the second coupling unit and the second pivot connecting member is configured to pivotally connect the second coupling unit and the third coupling unit, wherein the fastening element is configured to fasten the first coupling unit and the third coupling unit. 
     
     
         14 . The pipeline element coupling piece, as recited in  claim 13 , wherein each of the engaging surfaces of the first coupling unit and the third coupling unit defines a logarithmic spiral curve and the engaging surface of the second coupling unit defines an ellipse curve. 
     
     
         15 . The pipeline element coupling piece, as recited in  claim 14 , wherein the engaging surface of the second coupling unit has a middle point having a minimum radius of curvature which is equal to the radius of curvature of the groove circumference of the groove of the pipeline element. 
     
     
         16 . The pipeline element coupling piece, as recited in  claim 15 , wherein each of the pipeline elements comprises an enlarged coupling end portion, wherein each of the engaging surfaces of the first coupling unit and the third coupling unit has a distal end point, wherein a radius of curvature at the distal end point is not smaller than a radius of curvature of the enlarged coupling end portion. 
     
     
         17 . The pipeline element coupling piece, as recited in  claim 16 , further comprising transition points between the second coupling unit and the first coupling unit and between the second coupling unit and the third coupling unit respectively, wherein the transition points have the same radius or curvature. 
     
     
         18 . The pipeline element coupling piece, as recited in  claim 14 , wherein a deformation of each of the engaging surfaces results in deformed and varied radiuses of curvature thereof, wherein a variation range thereof is 13% to 21%. 
     
     
         19 . The pipeline element coupling piece, as recited in  claim 16 , wherein D′ denotes a distance between the proximate end point and the distal end point, wherein a deformation of each of the engaging surfaces results in variation of D′, wherein a variation range thereof is 14% to 22%. 
     
     
         20 . The pipeline element coupling piece, as recited in  claim 16 , wherein each of the engaging surfaces of the first coupling unit and the third coupling unit defines a logarithmic spiral curve having an equation of ρ=e θ , wherein θ has a range of 60° to 200°, wherein ρ a  denotes the radius of curvature of the engaging surface of the second coupling unit, ρ b  denotes the radius of curvature of the engaging surface of the second coupling unit, ρ A  denotes the radius of curvature of each of the engaging surfaces of the first and third coupling units, ρ B  denotes the radius of curvature of each of the engaging surfaces of the first and third coupling units, D1 denotes a diameter of the groove circumference of the groove, and D2 denotes a diameter of the enlarged coupling end portion, wherein ρ a =D1/2, ρ A =(Sp+R′)/2, ρ b =D2/2+R, and ρ B =D2/2, wherein R′ has a value range of 0.3-1 mm. 
     
     
         21 . (canceled) 
     
     
         22 . The pipeline element coupling piece, as recited in  claim 20 , wherein Da denotes a value of a minor axis of the ellipse curve of the second coupling unit, Db denotes a value of a major axis of the ellipse curve of the second coupling unit, Sp denotes a standard of the pipeline element, D1 denotes a diameter of the groove circumference of the pipeline element, and D2 denotes a diameter of the enlarged coupling end portion, wherein Da=D1, Db=Sp+R′, wherein R′ has value range of 0.3-1 mm. 
     
     
         23 . The pipeline element coupling piece, as recited in  claim 13 , wherein the fastening element includes a bolt and a nut for coupling with the bolt, wherein each of the first pivot connecting element and the second pivot connecting element is a connecting pin. 
     
     
         24 . The pipeline element coupling piece, as recited in  claim 1 , wherein each of the pipeline elements has an enlarged coupling end portion, wherein the at least one gasket includes a plurality of protrusions spaced apart with each other, which is configured to be pressed between the two enlarged coupling end portions of the two pipeline elements. 
     
     
         25 . The pipeline element coupling piece, as recited in  claim 1 , wherein the at least one gasket comprises a base body, two biasing elements integrally extended from the base body, and a retaining element integrally extended from a middle portion of the base body, wherein the retaining element includes a retaining body and a plurality of protrusions integrally extended from the retaining body and spaced apart from each other, wherein each of the biasing elements includes an extending portion integrally extended from the base body and a biasing portion inwardly and inclinedly extended from the extending portion. 
     
     
         26 - 30 . (canceled) 
     
     
         31 . A coupling method for coupling two pipeline elements by a pipeline element coupling piece, wherein each of the two pipeline elements has a groove and a groove circumference of a groove bottom of the groove, wherein the coupling method comprises step of:
 (a) receiving an enlarged coupling end portions of the two pipeline elements in two connecting end portions of the pipeline element coupling piece and aligning engaging keys of two or more coupling units of the pipeline element coupling piece, wherein each engaging surfaces of the engaging keys has a radius of curvature; and   (b) deforming the engaging surfaces of the engaging keys to increase contacting area around the corresponding grooves of the pipeline elements and the engaging surfaces, so as to retain the engaging keys in the corresponding grooves of the pipeline elements.   
     
     
         32 . The coupling method, as recited in  claim 31 , wherein the engaging surfaces define curves with different radiuses of curvature, wherein each of the curves is selected from a group consisting of one or a combination of a logarithmic spiral curve, an Archimedes spiral curve, a pascal spiral curve, an ellipse curve, and a high power curve. 
     
     
         33 . A coupling method for coupling two pipeline elements by a pipeline element coupling piece, comprising steps of:
 (A) sleeving a first coupling end portion of the pipeline element coupling piece on an enlarged coupling end portion of a first pipeline element of the two pipeline elements, and inserting an enlarged coupling end portion of a second pipeline element of the two pipeline elements into a second coupling end portion of the pipeline element coupling piece in such a manner that engaging keys of a plurality of coupling units are respectively aligned with the grooves of the first and second pipeline elements, wherein an engaging surface of each of said engaging keys has a variable radius of curvature, wherein a gap is defined between the engaging surfaces and a groove circumference at a bottom of the groove; and   (B) operating at least a fastening element to fasten two fastening end portions of the coupling units to reduce the gap between the engaging surfaces and the corresponding groove circumference at the bottom of the groove, so as to retain the engaging keys at the corresponding grooves.   
     
     
         34 . The coupling method, as recited in  claim 33 , wherein the engaging surfaces define curves with different radiuses of curvature, wherein each of the curves is selected from a group consisting of one or a combination of a logarithmic spiral curve, an Archimedes spiral curve, a pascal spiral curve, an ellipse curve, and a high power curve.